1. Field of the Invention
The present invention relates to antennas for transmission and reception of radio frequency communications in a plurality of RF bands concurrently using the same element. More particularly, the present invention relates generally to an antenna array formed of a plurality of wideband-capable antenna elements, or radiators, which is capable of operating at any frequency between 800 MHZ and 3000 MHZ at substantially 6 dBi. The resulting array has a circular radiation and reception pattern which may also be adjusted to radiate up or down depending on orientation of side engaged elements on substrates.
2. Background of the Invention
Since the inception of cellular telephones, cellular service providers have had the task of installing a plurality of antenna sites over a geographic area to establish cells for communication with cellular telephones located in the cell. From inception to the current mode of cellular broadcasting and reception, providers have each installed their own plurality of large external cellular antennas for such cell sites. Generally, such antennas or cable hookup is necessary to provide a television receiver with the required signal strength to provide a perfect picture and sound to the viewer.
In practice, cell sites are grouped in areas of high population density, with the most potential users. Because each cellular service provider has their own system, each such provider will normally have their own antenna sites spaced about a geographic area to form the cells in their respective system. In suburban areas, the large dipole or mast type antennas must be placed within each cell. Such masts are commonly spaced 1-2 miles apart in suburban areas and in dense urban areas masts may be as close as ¼-½-mile apart.
Such antenna sites with large towers and large masts are generally considered eyesores by the public. Because each provider has their own system of cell sites and because each geographic area has a plurality of providers, antenna blight is a common problem in many urban and suburban areas.
The many different service providers employ many different technologies such as 3G, 4G, GSM, CDMA. They also employ these technologies on bandwidths they either own or lease, and which are adapted to the technologies. Consequently, the different carriers tend to operate on different frequencies. Since conventional dipole and other cell antennas are large by conventional construction, even where the different providers are positioning sites near each other, they still have their own cell towers adapted to the length and configuration of the antennas they employ for their systems and which are adapted to their individual frequencies.
Since the many carriers and technologies employ different sized, large antennas, even if they wanted to share cell sites more often and antennas, the nature of the antennas used conventionally discourage it. The result being a plethora of antenna sites, some right next to each other, with large ungainly and unsightly antennas on large towers.
External antennas generally take the form of large cumbersome conic or Yagi type construction and are placed outdoors either on a pole on the roof top of the building housing the receiver or in an attic or the like of a building. These antennas are somewhat fragile as they are formed by the combination of a plurality of parts including reflectors and receiving elements formed of light weight aluminum tubing or the like having various lengths to satisfy the frequency requirements of the received signals and plastic insulators. The receiving elements are held in relative position by means of the insulators and the reflector elements are grounded together.
Assemblage of these antennas is required either by the user which may bend or break some of the elements during construction which must be replaced or the user may become injured by falling or the like or by an installer for hire either of which increase the already high economic cost of the antenna.
Externally placed antennas of this type are continually subjected to the elements. Even if not damaged or destroyed by the elements during harsh weather conditions over time these antennas will generally produce poor or reduced reception during extreme weather conditions or will gradually reduce their ability to produce acceptable reception over time due to mechanical decay.
In addition to the above deficiencies, this type of receiving antenna is aesthetically ugly.
Other antennas that are currently used are indoor antennas which are easy on the eyes but unacceptable for producing a good picture and sound. The most common and effective of these indoor antennas is the well known dual dipole type positioned adjacent to or on the television receiver and commonly referred to as “rabbit ears.” These antennas are generally ineffective for fringe area reception and are only effective for strong local signal reception. When low frequency signals reception is desired, the dipoles must be extended to their maximum length which makes the “rabbit ear” antenna susceptible to tipping over or interfering with or causing possible damage to any adjacent objects.
Cable systems are also currently used for delivering signals to television receivers. This system is highly successful for delivering picture perfect signals to a television receiver over a large range of frequencies. One of the strongest disadvantages to the cable signal delivery systems is the economic cost of installation and the periodic cost of the signal delivery to the user which can run as high as one hundred dollars monthly.
Satellite dishes, with their accompanying accessories, are another of the present methods of receiving television signals. This method is popular and successful for receiving signals from fixed in position satellites. Systems of this type require large diameter dishes generally in excess of six feet, and ideally about twelve feet, for receiving acceptable signal levels. Small dishes under two feet in diameter are presently unusable for all but the most powerful satellite transmitters. The acceptable sized dishes are ugly to view and because of size are hard to hide from sight. In addition, the systems as they exist today, are quite expensive and, therefore, are not available to all who desire to view picture perfect television reception.
There has not been a highly signal sensitive, visually attractive indoor television antenna until the emergence of the instant antenna. The radiator elements, or antenna elements herein disclosed, are capable of concurrent communications between users, and broadcasting sources, and adjacent antenna nodes having the same radiator elements in one or a wide variety of bandwidths.
The unique configuration of the individual antenna radiator elements provides excellent transmission and reception performance in a wide band of frequencies between 470 MHz to 5.8 GHz. Such performance in such a wide bandwidth is heretofore un-achieved and the single radiator element disclosed is capable of employment for reception and transmission in widely used civilian and military frequencies such as 700 MHz, 900 MHz, 2.4 GHz, 3.5 GHz, 3.65 GHz, 4.9 GHz, 5.1 GHz and 5.8 GHz. The radiator element actually has reasonable performance capabilities up to 1.2 gbps rendering it capable of deployment for antenna towers for concurrent reception and transmission of RF frequencies between 470 MHz to 5.8 GHz which is heretofore unachievable in a single antenna element. Such deployment will minimize the number of towers and antennas needed in a grid or communications web, yet provide for the maximum number of different types of communications from cellular phones to HDTV. Further, when employed at a home or business, the elements or arrays of elements will allow for a single formed antenna unit to communicate all the frequencies used by the home or office to various devices employing them, from a single unit concurrently.
3. Prior Art
Conventionally, cellular, radio, and television antennas are formed in a structure that may be adjustable for frequency and gain by changing the formed structure elements. Shorter elements for higher frequencies, longer elements for lower, and pluralities of similarly configured shorter and longer elements to increase gain or to steer the beam. However, the formed antenna structure, or node itself, is generally fixed in position for elements which may be adjusted for length or angle to better transmit and receive on narrow bands of frequencies of choice in a location of choice to serve certain users of choice. Because many communications firms employ many different frequencies, many different such individual antenna towers are required with one or a plurality of such towers having radiator elements upon them to match the individual frequencies employed by the provider for different services such as WiFi or cellular phones or police radios. This can result in multiple antenna towers, within yards of each other, on a hill, tall towers or other high points servicing surrounding areas. Such duplication of effort is not only expensive, it tends to be an eyesore in the community.
Further the conventional methods of electrically connecting the plurality of radiator elements within these towers similarly fall short. Typical power dividers/summers, employing transmission lines or wires are used to combine the incoming signals of the radiator elements to input into a central processor or the like. However, such typical methods fall short in accounting for electrical impedance, as well as the timing of the plurality of incoming signals. Such timing problems rise from unequal transmission line length or from placement of antenna elements in positions where signals arrive at different times. While modern receivers can be adapted to tune out and ignore such signals, this can decrease the signal strength to the device in need of it. As a result, along with the eyesore of having multiple antenna towers within yards of each other, transmitted and received signals, from separate antenna elements, may not be of the best quality. The same is true of assembled pluralities of antennas for home or office.
As such, when constructing a communications array such as a cellular antenna grid, or a wireless communications web, the builder is faced with the dilemma of obtaining antennas that are customized by providers for the narrow frequency to be serviced. Most such antennas are custom made using radiator elements to match the a narrow band of frequencies to be employed at the site which can vary widely depending on the network and venue. Also, a horizontal, vertical, or circular polarization scheme that may be desired to either increase bandwidth or connections. Further consideration must be given to the gain at the chosen frequency and thereafter the number of elements included in the final structure to meet the gain requirements and possible beam steering requirements.
However, such antennas once manufactured to specific individual frequencies or narrow frequency bands, offer little means of adjustment of their ultimate frequency range, and their gain since they are general fixed in nature. Further, since they are custom manufactured to the frequency band, gain, polarization, beam width, and other requirements, should technology change or new frequencies become available, it can be a problem since new antennas are required to mach the changes. Additionally, as noted, there is little to no consideration as related to improvement with how the individual radiator elements are combined, and conventional methods are continued to be employed.
Still further, for a communications system provider working on many different bands, with many frequencies, in differing wireless cellular or grid communications schemes, a great deal of inventory of the various antennas for the plurality of frequencies employed at the desired gains and polarization schemes must be maintained. Without stocking a large inventory of antennas, delays in installation can occur.
Such an inventory requirement increases costs tremendously as well as deployment lead time if the needed antenna configuration is not at hand. Further, during installation, it is hard to predict the final antenna construction configuration since in a given topography what works on paper may not work in the field. Additionally, what exact gain and polarization or frequency range which might be required for a given system, when it is being installed might not match predications. The result being that a delay will inherently occur where custom antennas must be manufactured for the user if they are not stocked.
This is especially true in cases where a wireless grid or web is being installed for a wireless communications. The frequencies can vary widely depending on the type of wireless communications being implemented in the grid, such as cellular or Wi-Fi or digital communications for emergency services. The system requirements for gain, and individual employed frequencies, can also vary depending on the FCC and client's needs.
Still further, the infrastructure required for conventional cellular and radio and other antennas, requires that each antenna be hardwired to the local communications grid. This not only severely limits the location of individual antenna nodes in such a grid, it substantially increases the costs since each antenna services a finite number of users and it must be hardwired to a local network on the ground.
A similar problem arises with the user of the various transmitted RF signals from these differing antenna sites, as well as from local transmission and reception sites for communications over Wi-Fi and bluetooth. The user of a device capable of receiving and transmitting over cellular, Wi-Fi, and bluetooth bands for instance, may have multiple antennas with each designed for a specific RF communication bandwidth and standard. This not only causes duplication and extra cost, but the placement of the different antennas on a small device such as a laptop computer or cellphone, must be precise in order not to cause interference from the adjacent-placed antennas on the same device.
As such, there is a continuing unmet need for an improved antenna radiator element, and a method of antenna tower or node construction, and for home and office antenna formation, allowing for easy formation and configuration of a radio antenna for two way communications such as cellular or radio for police or emergency services. Such a device would best be modular in nature and employ individual radiator elements which provide a very high potential for the as-needed configuration for frequency, polarization, gain, direction, steering and other factors desired, in an antenna grid servicing multiple but varying numbers of users over a day's time.
Such a device should employ a wideband radiator element allowing for a standardized number of base components adapted for engagement to mounting towers and the like. The components so assembled should provide electrical pathways to electrically communicated in a standardized connection to transceivers. Such a device, should employ a single radiator element capable of providing for a wide range of different frequencies to be transmitted and received. Such a device by using a plurality of individual radiator elements of substantially identical construction, should be switchable in order to increase or decrease gain and steer the individual communications beams.
Employing a plurality of individual wideband radiator elements, positioned in multiple points around a circle, such a device having one antenna configuration, should be capable of operating at any frequency between 800 MHZ and 3000 MHZ at about 6 dBi and have a circular radiation pattern that can radiate up or down depending on orientation. Further the elements should be “scalable” depending on the frequency range one desires to cover whereby elements having the correct high and low frequency reception configurations may be employed to match those required by the user.